Field
The present application relates to technology used in connection with a gateway for heterogeneous networking within a vehicle.
Description of Related Art
Automobiles have been equipped with an increasing number of electronic products. The electronic products have been provided with a wide variety of additional sensors and control devices. Some of the products connect to an external network. Accordingly, various types of network technology that can be used in automobiles has also been developed.
For example, parts historically operated using hydraulic components or mechanical components have been replaced with sensors. For example, to recognize the manipulation of a driver, an Electronic Control Unit (ECU) for controlling drive signals based on the manipulation, and actuators for actually generating operations in response to the drive signals, have been developed.
Since these parts are individually developed and integrated with automobiles in accordance with characteristics and purposes specific to automobiles, ECUs, such as an engine ECU and a transmission ECU, as well as control devices, such as an anti-lock braking system (ABS), and an airbag and Vehicle Dynamics Control (VDC), each have a strong tendency to be independent. For this reason, wiring and noise between the ECUs and the sensors has become problematic. Accordingly, an independent protocol for networking within a vehicle has become necessary.
A representative technology related to networking within a vehicle is Controller Area Network (CAN) communication. CAN communication supports various communication speeds ranging from a low speed to a high speed, and minimizes a ripple effect even when a specific node fails.
When a sensor and an actuator are simply connected without a control device, a Local Interconnect Network (LIN) communication protocol, which is simpler, slower and cheaper than CAN communication, can be employed.
Additionally, automobiles require higher bandwidth due to their higher performance and precision. In particular, a safety device, a steering device, and the like require determinism to ensure that a sensing signal reaches a controller within a specific period of time, or that a signal is transferred from a controller to an actuator within a specific period of time. However, even CAN communication is limited in ensuring these features. Accordingly, communication standards, such as Media Oriented Systems Transport (MOST), MOST2, IEEE 1394, etc., that are faster and have improved reliability have been proposed.
Moreover, since a number of the parts and functions employ their own communication specifications, a resultant complexity of vehicle network environments is extremely high.
After extensive trial and error, a consortium of leading automobile part providers, vehicle semiconductor providers and automobile manufacturers have proposed FlexRay communication.
While CAN communication is a collision detection-based contentious communication method, FlexRay communication is a communication method that is based on a time division principle and can support both deterministic data and non-deterministic data.
To maximally utilize bandwidth within a fixed time slot, FlexRay communication repeats a time slot with a single slot period divided into a static segment, a dynamic segment, a symbol window, and a network idle time. The static segment is an interval assigned for a relatively important deterministic transmission; the dynamic segment is an interval assigned for a wide range of event-based data not requiring a high determinism; the symbol window is an interval for the maintenance of a network and for a start of signaling; and the network idle time is an interval for synchronization.
Based on the above-described structure, FlexRay communication can deal with low- and high-speed applications using a single protocol, and can provide a transmission which minimizes error and effectively addresses scalability. Furthermore, in FlexRay communication, a specific master node does not control the overall network. Rather, in FlexRay communication, individual nodes perform synchronization and communication in cooperation with each other. The individual nodes may synchronize the local clocks of the individual nodes with a single common global clock through synchronization based on network idle time. FlexRay is faster and more reliable than CAN and certain other protocols.
Another promising technology for networking within a vehicle is vehicle Ethernet communication. Ethernet is a communication technology that has been sufficiently matured and widely used, and thus attracts attention because it can provide a network capable of providing fast speed while ensuring sufficient reliability and determinism at low cost. Ethernet is also easily extendible.
The development of automobiles has occurred such that many part providers and automobile manufacturers are together involved in problem solving. Often, the automobile manufacturers adopt solutions proposed by the part providers. Accordingly, there is an increasing possibility that electronic parts connected by more than one network protocol will coexist in a single vehicle.